Children who fit into one or more of the following conditions will not be considered eligible to take part in the study: (1) they are outside the age range specified; (2) they are not regularly enrolled and attending school; (3) they have a history of prior or current treatment with psychoactive drugs or psychotherapy; (4) they are mentally retarded (Overall IQ<80); (5) they have a main diagnosis differing from ADHD, including children with other psychiatric or neurological diagnoses